1. Field of the Invention
The present invention relates to a current switching device and a method for manufacturing the same, and more particularly to a current switching device which can used for switching current direction by operating a switching element with a rotary swing manner and a method for manufacturing the same.
2. Description of the Prior Art
Generally, a portable machine tool has advantages of convenience in carrying and easy operation. Owing to some portable machine tools must possess the function of switching running direction at any time for handling every kind of working conditions, it is necessary to design specific driving manners for achieving the purpose. One of the driving manners is to provide a current switching device for switching the running direction of the portable machine tool. The working principle of the current switching device is to reversely switch the input current and the output current of the portable machine tool, so as to repeatedly change the running direction of the portable machine tool.
Referring to FIG. 1, which is an exploded view of a conventional current switching device. The conventional current switching device A includes a base A100, a cover (not shown) and a switching element A200. The base A100 is made of plastic material, and there are four metal terminals A300 buried in the base A100. The four metal terminals A300 are arranged in a manner of partial circular symmetry, and the four metal terminals A300 are metal sheets with equal thickness and with the same plane. Furthermore, a pivot A110 is disposed on the base A100, and the pivot A110 is located on the relative center of the four metal terminals A300. The pivot A110 is provided to pivotally connect with the switching element A200, so that the switching element A200 can rotate around the pivot A110. Furthermore, two sets of contact piece A400 are disposed on the switching element A200 where the four metal terminals A300 are adjacent to, and each set of contact piece A400 can conduct neighboring two metal terminals A300. By way of the rotation of the switching element A200, the manner of the contact pieces A400 conducting electricity in the metal terminals A300 can be changed, so that the current direction can be altered and the effect of switching the running direction of the portable machine tool can be accomplished eventually.
In the above conventional current switching device, owing to the switching element A200 is disposed on the base A100 and can rotate 360 degrees, the configuration of the switching element A200 is usually a cylinder, and an accommodating space of the base A100 for accommodating the switching element A200 is also designed as an cylindrical recess, so that the switching element A200 can rotate smoothly. However, such a design occupies the most space of the base A100, and there is no more space can be utilized in the base A100, thus the overall volume can not easily be reduced and the functions can not easily be expanded.
Moreover, owing to the volume of the conventional current switching device A can not easily be reduced, and the dimension of the cylindrical design of the switching element A200 also can not easily be decreased, the material cost will be wasted.
In view of this, it is necessary to provide a novel current switching device, which can utilize the inner space much effectively, and the cost of material and manufacturing cost can be saved.